It is common practice to provide some form of seal at the margins of a closure such as a door, especially with an "outside" door one side of which is exposed to the weather. A particular problem exists at the bottom of the door which usually has a sill or threshold as part of the doorway opening and a cooperating member which is attached to the door itself and is movable therewith. Because the sill is subject to considerable wear, it is advantageously made of a hard, wear-resistant material. The movable member attached to the door, sometimes called a "sweep," must therefore be formed from a relatively flexible material in such a way that it cooperates with the sill to exclude wind, rain and the like.
Various efforts have been made to provide sill and sweep combinations which perform the necessary functions and are reasonably easy to install and durable. Examples of elements and combinations of these are found in the following patents:
U.S. Pat. No. 1,379,910; Glaser
U.S. Pat. No. 1,530,717; Foote
U.S. Pat. No. 1,795,853; Glass
U.S. Pat. No. 2,089,380; Kammerer
U.S. Pat. No. 2,167,958; Oftedal et al
U.S. Pat. No. 2,949,651; Hill
U.S. Pat. No. 3,273,287; Pease, Jr.
U.S. Pat. No. 3,323,256; Reahard et al
U.S. Pat. No. 3,374,580; Ruff
U.S. Pat. No. 3,900,967; Bursk et al
However, these structures exhibit numerous shortcomings and, generally, are quite difficult to install on existing door structures. Common disadvantages are the need to alter the configuration of the door bottom to receive the sweep portion and the relative lack of adjustability to accommodate varying gaps between sills and door bottoms.